This application is a National Stage Entry of International Application No. PCT/KR2016/003387 filed on Apr. 1, 2016, and claims the benefit of Korean Application No. 10-2015-0047681, filed Apr. 3, 2015, all of which are hereby incorporated by reference in their entirety for all purposes as if fully set forth herein.
As IT and semiconductor industries have greatly developed in recent years, the production quantities of related products, such as TFT-LCD, have been increasing. Accordingly, the amount of waste emitted from manufacturing processes is also rapidly increasing. In particular, in manufacturing processes of TFT-LCD array circuit boards, a photoresist stripping solution (hereinafter referred to as “stripper”) is used to remove a photoresist, particulate residues, debris, and denatured materials which remain after gate pattern formation and metal film etching in a stripping process of a photoresist. The amount of an organic solvent used in the stripper has reached about 30,000 tons each year and the cost of the organic solvent is highest among the costs of raw materials. Accordingly, a need for recycling of waste stripper solutions is increasing.
For example, since waste stripper solutions used in the manufacturing processes include impurities, such as photoresist resins, moisture, heavy metals, etc., in addition to organic amine compounds and organic solvents, a process of separating organic solvents and photoresist resins from the waste stripper solutions is required. Conventionally, organic solvents and organic amine compounds were collected from the waste stripper solution containing water, organic amine compounds, organic solvents, and stripped photoresist resins using a distillation device in which two distillation columns are sequentially connected. However, during this process, there was a problem of a large amount of energy loss.
Therefore, there is a need for a stripper solution purification process that allows separation of high-purity organic solvents and organic amine compounds while reducing installation cost of a distillation device and energy consumption.